# Removed and reserved statement words

Several readable ideas are intentionally not source-language features yet. The compiler rejects them with a supported replacement instead of silently inventing behavior.

Last updated: 2026-09-09

Package: language | Status: unavailable

Tags: assert, boundaries, channel, choice, const, cpu, emit, endLoops, event, export, fatal, finally, language, panic, thread, watch, yeho

Use the replacement that makes ownership and flow explicit. Revisit dedicated syntax only after it earns a compiler, runtime, and verification contract.

```yh
choice -> enum
channel -> tunnel
export -> external
event / emit / watch -> functions + tasks + tunnels
assert -> explicit if + error result
thread -> task
const -> ordinary typed field or variable
endLoops -> structured return, error, or narrow loop control
```


## Complete program

A complete supported message handoff. event/emit/watch/channel are unavailable spellings; tunnel is the working alternative.

Verification: type checked

```yh
// Event declarations are unavailable. Use the admitted tunnel contract.
tunnel of text notices
notices.Send("player ready")
text message = notices.Receive()
Console.Log(message)

```

Save this beside start.yh as project.mech:

```toml
manifestVersion = "2"
package = "api.example.language__rejected_words"
version = "0.1.0"
languageEdition = "yeho-core-2026.1"

[app]
kind = "headless"

```

Extract the example archive beside the yeho and dolphin checkouts. This example requires those source dependencies and a current developer compiler.

```sh
./yeho/build/dolphin-metal/yehoc ./api-examples/language--rejected-words/complete --backend cpu-oracle -o /tmp/yeho-example
/tmp/yeho-example
```


panic, assert, fatal, exception subclasses, and finally are not admitted error syntax.

Dedicated event, emit, and watch syntax is deferred in favor of ordinary values, functions, tasks, and tunnels.

Source: yeho/parser_core.cpp and parser_statements.cpp rejection diagnostics; language-core.md §13.4

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